GLYWT series Programmable Microcomputer Hydro-governor (PMH) is applied in medium and small-sized water-turbine electricity generator sets. It is united cabinet of controller, mechanic and hydraulic system. High stability Programmable Logic Controller (PLC) is the controller. High oil pressure devices, digital and standardization design are adopted in mechanical part. It takes high quality standardized digital hydraulic valves as actuators, easy for replacement and system update. Such simplifies system structure of PMH, avoids complication and low stabilization of traditional Hydro-governor.